In the marine shipping industry, the expected annual container traffic growth is from 4.7% to 7.6%. Container terminals are faced with the challenge of maintaining the inventory control for these escalating numbers of containers. The input, ouput and storage of containers at these terminals must provide an efficiency level that is at least consistent with, or exceeds, past performance.
Present and future growth levels have compelled terminal management companies to look for new systems to bring about more efficient resource control and, as a consequence, provide a more profitable operation.
Shipping companies wish to reduce the time a ship spends at port in order to increase the productivity of each vessel. Increasing the productivity of berthing operations allows ships to be loaded and unloaded faster, effectively reducing the time spent at port.
What is needed by both terminal management and shipping companies is a more accurate, real time accounting of incoming, outgoing and existing container inventory. A more efficient container inventory management system is needed to minimize the time spent at a port or rail yard loading and unloading containers.
FIG. 1 illustrates a typical berthing process, involving quay container cranes 2200, transports between quay container cranes 2200 and storage yards, and storage yard containers manipulated by transfer container cranes 2100, as found in the prior art.
The berthing operations involve the transport of containers between container ships and the storage yard. Currently, quay container cranes 2200 access the containers from above ships 220 and move them to and from transportation units 210, such as trucks, each with a chassis, or Automatically Guided Vehicles (AGV's). The vehicles deliver the containers to storage yards 200 where other vehicles transfer the containers to stacks. The berthing process involves three operations: (1) quay container crane 2200 handling, (2) quay container crane 2200 to storage area 200 transport, and (3) storage area 200 manipulation often by one or more transfer container cranes 2100 as illustrated in FIG. 1.
Generally, there are two kinds of storage yards 200, wheeled storage yards 200 and stack (or ground) storage yards 200. For a wheeled storage yard 200, each container is on a chassis and there is only one container on a chassis. For a stack (or ground) storage yard 200, containers are stacked up to 5 levels high.
The quay container crane 2100 and transport vehicle 210 operations are highly interdependent. A delay in one operation causes the other to pause, reducing the overall productivity of the berthing process. If there are mistakes in these operations, then the overall berthing process is seriously delayed.
What is needed is a method for reducing errors and supporting efficient operation of the berthing process.
FIGS. 2A and 2B illustrate typical container codes and their representation on the side of a container as found in the prior art.
Each cargo container 100 is assigned a unique identification number 110 displayed on the sides and roof of the container. This identification number is represented in the form of a painted code and ID tag. Numerous government agencies and ship regulators require container codes on all containers. As a result, the painted container code representations of numerals and letters are used universally and internationally, as shown in FIGS. 2A and 2B.
A magnetic tag is another prior art method assigning an identification number to a container. However, the magnetic tag method suffers from several problems. The magnetic tag method is not an international standard. Magnetic tags for containers are only installed by individual shipping line owners at their discretion. Not all container transporters support magnetic tags for their containers.
Additionally, a magnetic tag must pass in close proximity to a magnetometer in order for the magnetic tag to be read. The container passing the magnetometer can be outbound and inbound. Moreover, the magnetically tagged container can be moved anywhere. Magnetic tag reading provides no information about the container's physical location.
Another prior art alternative can identify containers from a distance. It is a technically more sophisticated and expensive system requiring a transponder tag attached to each container. The transponder tags can be programmed to show different kinds of information in the form of a coded signal when interrogated by a radio frequency transceiver. Such systems are expensive, delicate, and easily damaged.
Cargo containers are the individual property of the different shipping lines. When used by a non-owner shipping line, a container rental fee is paid to the owner. At the present time, the shipping companies only know the size of each container and whether it is dry or refrigerated.
A cargo container can become lost for several reasons. Inadvertently, a container is misplaced in a different location (yard address). Sometimes a container crane operator leaves a container at the wrong address, causing the container to be lost. A computer tracking the containers parked in a container terminal storage area will have an error in the container's tracking data. As a result, the lost container is effectively invisible to the existing container terminal management system (CTMS). While this is usually discovered eventually, the container is inevitably lost for a certain time.
A cargo container can become lost when the container ID number is incorrectly input into the CTMS. A cargo container can become lost when the container ID number is unreadable due to dirt, scratches, being covered, or an incorrect label on the container.
Any of these errors can result in disruptions of the inventory database. In addition, these errors become particularly serious when one attempts to place a second container into a supposedly vacant location only to find the location is already occupied, which further results in time consuming interruptions. What is needed is an efficient way to track all the containers and update an inventory database. What is further needed is an efficient way to track all containers in both wheeled storage yards and stack storage yards.
It can take a week in a major container storage yard to find a lost container. This can delay a ship's departure and/or the container's delivery to its destination. Either and/or both delays cost the shipping companies money.
Today, there is a large turnover of cargo containers in the seaports. This cargo turnover makes it necessary to regularly update the CTMS database. What is needed is an automated method of updating the CTMS database in real-time that will work efficiently even during the rush hours.
Today, a known disclosure teaching automatic reading of container ID tags on container cranes, is found in U.S. Pat. No. 6,356,802 entitled “Method and apparatus for location cargo containers”, by Takehara (one of the inventors of this application) and Ng. The '802 patent is assigned to the same assignee as this application, Paceco Corp. The '802 patent discloses “The system can be installed on cranes to identify containers at wharfside and on straddle carrier cranes for identifying containers in single or multiple stack container storage. The system can be installed on cranes to identify containers mounted on rail cars in rail terminals . . . ” (Lines 50–55, Column 4)
“The machine reader, its associated apparatus, and the LDU, are carried onboard a transporter such as a cart which runs on tracks or can be steerable. The cart can either be operator driven or remotely controlled. The apparatus could be mounted onboard the storage yard patrol truck. . . . The machine reader can be alternatively aimed by the transporter, remotely controlled, or handheld by an operator.” (lines 40–48, Column 6) Note that “LDU” is disclosed as “location determining unit” in line 1 of Column 6.
“. . . the present invention contemplates wireless transmission of the data from the machine reader/transporter to the central terminal where the CTMS is located for real time data updating. This can be accomplished by a wireless modem, or a communication unit, which transmits the container's ID number and its current location back to the stationary central computer which hosts the CTMS program and also contains the inventory database.” (line 65 Column 6-line 6 Column 7) CTMS refers to container terminal management system (line 12 Column 3).
“The identification means is scanned from a distance by a machine such as an optical character recognition (OCR) unit to interrogate the ID tag and identify the container. It is an important characteristic of the invention that an operator of the system is able to remotely interrogate an ID tag of a cargo container . . . without the necessity of physically approaching and contacting the container or even coming in close proximity thereto.” (lines 3–10 Column 5)
While of value, the '802 patent fails to disclose or teach at least the following:    1. How to track containers in stack storage yards, which may pile containers as many as five levels high.    2. There are advantages to monitoring cargo container operations by a container crane either through sensing the control system of the container crane, or through the use of sensors external to the container crane's control system.    3. Real-world optical character recognition systems occasionally make mistakes or are unable to recognize the characters, often requiring reliability estimates of the recognized container ID.    4. There is a practical requirement for an automatic container code reading machine to send a version of the image(s) captured by its video imaging device(s) to a remote operator. This again stems from the real-world limitations of optical character recognition systems at recognizing the characters.    5. There is a practical requirement for the machine to minimize bandwidth in sending the video image(s) across at least a wireless physical transport layer.    6. There are significant advantages in many real-world situations for the machine to have multiple video imaging devices placed apart from at least each other, rigidly affixed to the container crane. Such advantages include the ability to withstand the severe mechanical vibrations container cranes experience, while providing container code observations from various locations about and around the container crane, which include providing the length of the cargo container.    7. There are further advantages to positioning multiple, independently controlled lighting systems to improve the imaging quality of the multiple video imaging devices.
To summarize, what is needed by both terminal management and shipping companies is a more accurate, real time accounting of incoming, outgoing and existing container inventory as the container cranes act upon and around the containers, particularly with regards to stack storage yards.
What is needed is a method of reducing errors and supporting efficient operation in the berthing process through the automated monitoring of cargo container loading and unloading.
What is needed is an automatic container code reading machine sending a version of the image(s) captured by its video imaging device(s) to the remote operator. The bandwidth needs to be minimized in sending video image(s) across at least a wireless physical transport layer. The machine needs, in many real-world situations, to include multiple video imaging devices placed apart from each other and rigidly affixed to the container crane. Multiple, independently controlled lighting systems may further be needed, positioned to improve the imaging quality of the multiple video imaging devices.
Note that the problems discussed herein also relate to rail yard container inventories as well.